There is proposed a technique that allows taking panned images having a stationary main subject portion and a flowing background portion without accurately panning a camera to follow a moving main subject. An example of such technique is disclosed in JP-A-2006-339903.
In the technique described in the publication, JP-A-2006-339903, when taking a panning shot, consecutive shooting is performed in response to a command to shoot an image. Then, a plurality of images taken by the consecutive shooting are combined while the images are positioned so that main subject portions overlap on ore another at the same position. In combining the images, first, the plural images are compared with one another and plural consecutive regions which are larger than a given size and in each of which pixel, values and their arrangement patterns are substantially the same are extracted from the entire image. Then, motion vectors are acquired for the respective extracted regions and regions having different motion vectors are recognized as different subject regions. Then, one of the recognized subject regions is employed as a region corresponding to a main subject, and the images are combined with this region used as a reference region in such a manner that main subject portions overlap on one another at the same position.
However, in the above technique, in combining plural images, in order to determine a reference region that is required for positioning the plural images, processing of comparing the plural images and extracting, from the entire image, consecutive regions which are larger than the given size and in each of which pixel values and their arrangement patterns are substantially the same is required. Accordingly, the process for positioning and combining plural images requires a considerable amount of processing power and takes a considerable amount of time.